My 75-E has a 2-3/8 mast exactly. I can see my FTA dish mount supporting a my 3f prime dish, because it has 2 support legs for an extra sturdy mounting. But my old
dish 500 mount, I don't see it being able to support that big ol' dish in wind gust up to 25-30 mph or higher. My 31" Fortec wobles enough in light gusts, but much to my surprise I lose no signal strength! If I mounted my 3' prime dish on that dish 500 mount, it would just get ripped off the side of my house in our windy march weather! lol!

But I suppose if you had the thing mounted to a solid surface and had long lag bolts, It could withstand windy weather.
-Will